Abstract
The probability of simultaneous emission of an x-ray photon and an electron is considered. It is shown that this process can occur as a consequence of the change in the average potential acting on the electrons when the x-ray hole is moving from an inner to an outer shell (shake-off) and as a consequence of interaction between single- and double-hole configurations in the final state. Relative shake-off probabilities of KL2, KM2, and L2,3M1M2,3 transitions are calculated for F, Ne, Na+, Cl, Ar, and K+ from Bagus's self-consistent-field wave functions of single-hole x-ray states. The relative probability of KL2 and KM2 transitions is estimated for the rest of the atoms in the range 9<~Z<~22. The estimated KL2 and KM2 probabilities are of the same order of magnitude as the observed probabilities. However, for low Z, they overestimate the observed probabilities, which may be because the shake-off calculations do not account properly for the interaction between single- and double-hole configurations in the final state.